Fig. H1. A schematic view of relevant interactions between aerosol particles, the environment, and approaches to study them in the laboratory and with numerical models.[Source: figure by A. Zuend]

Atmospheric aerosols – tiny particles suspended in the air – are of fundamental importance for urban and regional air quality, clouds and the global climate system. Aerosols are among the least understood and quantified climate agents, affecting Earth’s radiation balance directly as well as indirectly via their crucial role in the formation of cloud droplets and influence on cloud microphysics. Part of the lack of knowledge is due to the complexity and variety of primary and secondary particle sources, the chemical composition, phases, and physical states of aerosols and the evolution of these properties by means of chemical and physical processing in the air.

Our research projects are motivated by the need to understand, on a quantitative level, the chemical thermodynamics, reactions, and mass transfer kinetics of complex mixtures consisting of tens to thousands of oxidized organic compounds, water, and inorganic salts and acids that form and characterize the majority of secondary aerosols in the troposphere. Learn more about current activities on the Research page.

November 23, 2017: Looking for the AIOMFAC website? The AIOMFAC model website hosted at Caltech, http://www.aiomfac.caltech.edu, has suffered some downtime during the past days due to necessary server hardware repairs. To avoid longer unavailabilities in future, the AIOMFAC model website is now also hosted on a server at McGill University, currently accessible via the following URL: http://web.meteo.mcgill.ca/aiomfac/.

June 21, 2017: Our research collaboration work titled Surface tension prevails over solute effect in organic-influenced cloud droplet activation has just been published by Nature online - doi:10.1038/nature22806. See also the brief overview here.